Pass ref param from repo preview file to Pipeline editor section to preserve current branch

What does this MR do and why?

When previewing a CI config file in the repository, you have the option to edit it by going to the pipeline Editor. However currently if you are on a different branch from the default branch, it will not be preserved when navigating to the Pipeline Editor. To fix this, we pass the query param ref with the current branch as value and the Editor will load on the correct branch!

Screenshots or screen recordings

These are strongly recommended to assist reviewers and reduce the time to merge your change.

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.